Airfoil arrangement with ptal bond coating and thermal barrier coating, and corresponding manufacturing method

Abstract

An airfoil with a coated surface section which having a platinum aluminide and a TBC coating is provided herein. Furthermore, an airfoil arrangement for a gas turbine including an airfoil, an inner shroud, and an outer shroud, wherein the airfoil is arranged between the inner shroud and the outer shroud, wherein the airfoil comprises a coated surface section which is coated with a platinum-aluminide coating and a thermal barrier coating and which represents at least a part of the total surface of the airfoil, wherein the thermal barrier coating of the coated surface section is spaced from the inner shroud and / or the outer shroud with a distance (x) and wherein the distance (x) is between 5% and 25% of a total length of the airfoil between the inner shroud and the outer shroud is provided herein.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2013 / 056343 filed Mar. 26, 2013, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP12167242 filed May 9, 2012. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The present invention relates to an airfoil, an airfoil arrangement for a gas turbine with a PtAl (Platinum Aluminide) coating and TBC (Thermal Barrier Coating) and to a method for manufacturing an airfoil arrangement for a gas turbine.ART BACKGROUND[0003]The stator vanes and the rotor blades in a gas turbine are exposed to the high temperature of the working fluid passing the vanes and the blades. Due to the high temperature a significant oxidation of the base alloy can occur at the leading edge of an airfoil of the stator vane or, the rotor blade. Furthermore, oxidation at the inner plat...

AI Technical Summary

Benefits of technology

The patent describes a coating system for airfoils that helps to protect against high temperatures and corrosion. The system includes a coating made of platinum-aluminide (PtAl) which reduces the temperature of the airfoil and also acts as a bond coat for a ceramic thermal barrier coating (TBC). This system provides better protection against oxidation and corrosion, and increases the life of the airfoil. The coated surface section covers the airfoil from the leading edge to the trailing edge along both the suction and pressure sides. Overall, this coating system improves the thermal protection and increased lifespan of airfoil arrangements.

Problems solved by technology

Furthermore, oxidation at the inner platform of the inner shroud and / or outer shroud of the stator vane or the rotor blade can also occur.

Such degradation is currently the life limiting mechanism on this component.

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